Method of adjusting the lip opening of an extrusion die for stratiform material and the therefor applied extrusion lip

Description

[0001] This invention relates to a method of adjusting the lip opening of an extrusion die for stratiform material, particularly for extrusion dies of the type that mainly consists of, on the one side two lips and the like, forming the lip opening, and on the other hand, a number of control units put across the width of the lip opening, which all consist of one or more bar shaped elements, expansive by heat, respectively shrinkable by cooling which act upon at least one the lips in order to displace them and to change the lip opening. These dies are appropriate for the extrusion of film and coating as well as for the extrusion of sheet and the like.

[0002] An extrusion die of said type is known from the U.S. patent N^o. 3 940 221. This known extrusion die mainly consists of a die block in which an oblong opening is provided through which a more or less liquid material may be pressed by extrusion to form a layer, whereby the opening is limited on one side by a flexible lip which may be moved by expansive, respectively shrinkable, bar shaped elements in order to modify the opening width. The heating, respectively the cooling, of the bar shaped elements is hereby done by means of heat-conducting blocks which are provided individually for each bar shaped element, and which, parallel to the bar shaped elements, each consist of a heating element and a cooling channel.

[0003] Although such an arrangement theoretically enables a proper control of the lip opening, it shows the practical difficulty of distributing the cooling medium over a large number of cooling channels in such a manner that approximately the same amount of cooling medium is delivered to each cooling channel. So it is rather difficult to provide a uniform cooling effect in all the bar shaped elements.

[0004] Moreover, such an arrangement shows the disadvantage that, when one cooling channel fails, the corresponding bar shaped element doesn't receive any more cooling at all. The increased activity of this element, originated by this condition, also influences the adjacent bar shaped elements, which eventually results in a total deranging of the system.

[0005] At the same time, with the known arrangement, the cooling channels are located between the bar shaped elements and the heating elements. From this the disadvantage arises that a considerable supply of energy to the heating elements is required to provide the bar shaped elements with an encreased heat supply, opposite to the cooling.

[0006] Further, this known extrusion die also shows the disadvantage that the control of the lip opening is very susceptible to the changes of the ambient parameters. This is, amongst other things, due to the fact that the bar shaped elements, in order to fasten them, are in contact with the die block over a comparatively large distance, so that a considerable heat bridge is existing between the die block and these elements.

[0007] Extrusion dies for the extrusion of stratiform materials are also known form US 4.252.519 and JP-58 65 631.

[0008] Document JP-58 65 631 discloses a die which is of the same type as the die shown in US 3.940.221 and consequently shows the same disadvantages.

[0009] US 4.252.519 discloses an extrusion die having heat barrier means between the heater elements used for the adjustment of the opening and the lip of the die. This document however does not disclose the use of cooling means acting on the adjustment means. Such an arrangement does not enable the proper control of the lip opening.

[0010] Thus, the present invention also relates to an extrusion die for the extrusion of film, coating, sheet and the like, showing none of the said disadvantages nor other ones.

[0011] The present extrusion die has the advantage that in the surroundings of the bar shaped elements a considerable uniformity of the temperature is reached, whereby also various temperature influences, by air currents and heat bridges, are leveled out. By this, one obtains also a uniform radiation of heat to rolls possibly positioned in the surroundings of the die, so that the disadvantage of the so called hot spots is avoided. Another advantage of the extrusion die according to the present invention consists in the possibility of operating with lower mean temperatures of the bar shaped elements, so that one obtains that the temperatures of the system may be adjusted in such a manner that the time constant of the cooling is almost equal to the mean time constant of the heating of the bar shaped elements. As it is known, this is a primary requirement to enable a proper control. By an operation at lower temperatures a smaller difference between the temperature of the device and the ambient air is obtained, whereby the influence of the surroundings on the system is considerably reduced. The extrusion die also shows the advantage that the bar shaped elements are very well shielded against external influences, whereby it is obtained that, when the control system and/or the power supply fail the extrusion die easily may continue to operate by means of manual control.

[0012] The extrusion die according to the invention shows also the advantage that, thanks to the method applied to control the lip opening and more specially to cool the bar shaped elements, the bar shaped elements keep receiving a sufficient cooling when one cooling channel fails.

[0013] The said advantages are mainly obtained by the application of a method for the control of the lip opening of an extrusion die, whereby the extrusion die is of the type that mainly consists of, on the one side, two lips forming the lip opening, and on the other hand, a number of control units put across the width of the lip opening which all consist of at least one bar shaped element, expansive by heating, respectively shrinkable by cooling which act upon at least one of the lips in order to displace them and to change the lip opening, and whereby the method for the control mainly consists of the combination of, on the one side, the control of the heating of the bar shaped elements by each control unit in function of the local thickness checks which are carried out across the width of the formed layer of material, and one the other hand, the common cooling of several control units by forcing a cooling medium mainly transversally along several bar shaped elements.

[0014] According to a preferred method according to the invention also the temperature of the common cooling medium at the supply thereof will be controlled in combination with the said.

[0015] In view of a better demonstration of the characteristics, hereafter, as examples without any restrictive character, some preferred embodiments are described referring to accompanying drawings, wherein:

figure 1 lines out the followed method for the adjustment of the lip opening of the extrusion die;

figure 2 shows a section of an extrusion die for the embodiment of the method according to the invention;

figure 3 shows a side view according to arrow F3 in figure 2;

figure 4 shows a perspective drawing of the cooling blocks which are used in the embodiment according to the figures 2 and 3.

[0016] As outlined in figure 1 the extrusion die consists mainly of a die block 1 showing an extrusion discharge opening 2 along which more or less liquid material 3 by means of extrusion may be pressed into a layer 4. Hereby the lip opening 5 of the extrusion discharge opening 2 is determined by means of two lips, respectively 6 and 7, whereby according to these embodiments the upper lip 7 is executed elastic and flexible.
Further, across the width of the lip opening 5 a number of control units 8 fitted, each consisting of one or more bar shaped elements, expansive by heat, respectively shrinkable by cooling which may co-operate on one end with a steady support 11, whilst they may co-operate on the other end 12 with the said elastic lip.
Hereby the bar shaped elements 9, according to the type of embodiment, apply either a compression of or a tension on the elastic lip.

[0017] The most important characteristic feature of the present invention consists in the control of the lip opening 5 according to a method which mainly consists in the combination of, on the one side, the control by each control unit 8 of the heating of the bar shaped elements 9, and on the other hand, the common cooling of several control units by forcing a cooling medium mainly transversely along several bar shaped elements 9. This movement of the cooling medium is outlined in figure 1 by means of the arrows 13 and 14. As a matter of fact a lot of variants are possible to force the cooling medium transversally with respect to the bar shaped elements 9, which will be described further hereafter.

[0018] Another important characteristic of the preferred embodiment of the invention consists in the heating of the bar shaped elements 9 by means of heating elements 15 which are put internally in the bar shaped elements 9 and which are controlled by each control unit 8.

[0019] In figures 2, 3, and 4 a practical embodiment is shown. Hereby the extrusion die shows mainly the same characteristics as outlined in figure 1.

[0020] In order to provide the transversal cooling, two cooling blocks, respectively 16 and 17, are employed, of several adjacent sets of each time two of such cooling blocks 16 and17 which may be fastened against each other, e.g. by means of bolts 18, thereby enclosing the bar shaped elements 9. For this purpose each of these cooling blocks 16 and 17 are provided with opposite semicircular recesses 19 and 20 which may enclose tightly the bar shaped elements 9. Transversally with respect to these recesses 19 and 20 a number of hollowings, respectively 21 and 22, wherein cooling channels are provided, respectively 23 and 24, are applied.

[0021] The extrusion die is provided with means, respectively 25 and 26, to provide the supply and the discharge of a cooling medium. As shown in figure 3 according to this embodiment the means 25 and 26 consist of four collectors 27, 28, 29 and 30. Hereby the cooling channels 24 of the external cooling block 17 are connected with their inlets and outlets respectively to the collectors 27 and 28, while the cooling channels 23 of the internal cooling block 16 are connected with their inlets and outlets respectively to the collectors 29 and 30. Further inlets 31 and 32, as well as outlets 33 and 34 are properly provided to the said collectors in order to provide the supply and discharge of the cooling medium.

[0022] The direction of flow of the cooling medium in the external cooling block 16 is opposite to the direction of flow of the cooling medium in the internal cooling block 16.

[0023] According to the preferred embodiment the bar shaped elements 9 are fastened with their lower ends 12 and their upper ends 10 between respectively the upper lip 7 of the lip opening 5 and bolts 35 which are screwed in the steady support 11. The bolts 35 allow a manual adjustment of the lip opening 5.

[0024] To avoid the control units 8 causing modifications of the temperature in the actual die block 1, an insulating layer 36 is put between each internal cooling block 16 and the die block 1. To limit the influences from outside also an insulating layer may be put at the exterior, e.g. against each external cooling block 17. To avoid the expansion or shrinkage of the bar shaped elements 9 by the fluctuations of the ambient temperature according to the present invention the contact surfaces between the bar shaped elements 9 and the die block 1 are preferably minimized. According to the figures 2 and 3 this realized by the application of concentric recesses 37 in the die block 1 around the bar shaped elements 9.

[0025] The bar shaped elements 9 are internally provided with preferably electric heating elements 15 whereby, not shown on the figures, means are applied to control the supply of the electric energy to said heating elements. These means mainly consist of an voltage level control, an adjustable pulse generator or a frequency regulator.

[0026] The control of the heating elements may be done according to prior art manually as well as automatically in function of the measurement of the thickness of the manufactured layer 4. This measurement may be realised according to the prior art by means of mechanical sensors, radiation sensitive detectors or other measuring techniques. This measurement may be executed by hand or automatically.

[0027] The cooling medium according to the invention may be a gas or a liquid, e.g. air or water. According to the invention the temperature of the cooling medium may be controlled. Naturally, in the latter case a temperature control is provided to the supply, e.g. a cooling device, which is not shown in the figures. Such a control has the advantage that one can intervene very quickly in case of an unwished disturbance. In this way, in the event that a bar shaped element 9 gets overheated, due to any possible reason, may be prevented that the lip opening 5 gets locally closed and the layer 4 is interrupted, by providing an abrupt decrease of the temperature of the cooling medium.

[0028] Naturally such a temperature control of the cooling medium on itself is also applicable to the prior art extrusion dies.

[0029] It is obvious that the transversal cooling according to the invention may occur in an other manner than described above. In such a way, e.g. the directions of flow of the cooling medium in the cooling channels of the internal and the external cooling blocks, respectively 16 and 17, may be identical to each other.

[0030] According to another variant of the invention the transversal cooling channels may be combined at their ends in such a way that they show a course with a meander form.

[0031] According to a variant the extrusion die comprises or more single or composite cooling blocks, in other words whereby no separate internal and external cooling blocks are used. Then traverse bore holes are provided instead of the said recesses 19 and 20 into which the bar shaped elements 9 are put. It is obvious that the extrusion die may be provided with several cooling blocks which are put in juxtaposition, whereby each said cooling block e.g. may be bipartite and may consist of an internal and an external cooling block 16 and 17, either can be one-piece on itself, or may have any other shape and composition. Between the adjacent cooling blocks preferably a small free space is left, in order to allow the expansion of the cooling blocks.

[0032] According to another variant which is not shown in the figures the cooling channels 23 - 24 are provided, on the ends which are positioned in opposition to the bar shaped elements 9, with cooling fins which are shielded with sheets. The in this manner formed additionally cooling channels are fed by means of a forced air current.

[0033] According to still another variant the cooling blocks are provided with cooling channels which are exclusively formed by the said shielded fins.

[0034] There is no need to do the heating of the bar shaped elements 9 by means of electric heating elements, and in other words it may be achieved in any manner, e.g. by means of oil or by heating by ultrasonic vibrations.

[0035] It is obvious that the lower lip 6 as well as the upper lip 7, or both lips 6 and 7, may be provided with the said control of the lip opening.

[0036] Naturally the invention relates also to extrusion dies with several distribution channels, whereby possibly different kinds of material 3 are pressed through the same extrusion opening 2, as well as to dies which have several extrusion openings 2 adjacent to or above each other. The invention is also applicable with extrusion dies whereby a multi-layered extrude is formed.

[0037] The present invention is by no means limited to the embodiment described as examples and shown in the accompanying drawings, but such an extrusion die as well as the composing parts thereof may be realised in all kinds of forms and dimensions without leaving the scope of the invention as set out in the claims.

Claims

1. Method for the adjustment of the opening of the lips of an extrusion die for stratiform material, whereby the extrusion die of the type that mainly consists of, on the one side, two lips (6-7) forming the lip openings (5), and on the other hand, a number of control units (8) put across the width of the lip opening (5), all of them being composed of at least one bar shaped element (9), expansive by heating, respectively shrinkable by cooling, able to act upon at least one of the lips (6-7) in order to displace them and to change the lip opening (5), with the characteristic that the method of the adjustment mainly exists in the combination of, on the one side, the control by each control unit (8) of the heating of the bar shaped elements (9) as function of the local checks of the thickness which are executed over the width of the formed stratiform material (4), and on the other hand, the common cooling of several control units (8) by forcing a cooling medium mainly transversally along several bar shaped elements (9).

2. Method according to claim 1, with the characteristic that the temperature of the supplied cooling medium is controlled.

3. Extrusion die for the application of the method according to claim 1 or 2, comprising the combination of two lips (6-7) forming a lip opening (5) along which the material can be pressed continuously into a layered shape (4), a number of control units (8) put across the width of the lip opening (5), all of them being composed of at least one bar shaped element (9), expansive by heating respectively shrinkable by cooling, able to co-operate with at least one of the mentioned lips (6-7) in order to displace them and so to change locally the lip opening (5); heating elements (15) fixed along each of the bar shaped elements (9) and controlled by each control unit (8); and cooling means to cool several control units (8), characterized in that said cooling means consist in one or more cooling channels (23-24) extending transversally along the bar shaped elements (9).

4. Extrusion die according to claim 3, with the characteristic that the cooling channels (23-24) are fixed in or against one or more cooling blocks (16-17) made from properly heat conducting material, which enclose the bar shaped elements (9).

5. Extrusion die according to claim 4, with the characteristic that the cooling channels (23-24) are applied in at least one internal and/or at least one external cooling block (16-17).

6. Extrusion die according to any of claims 3 to 5, with the characteristic that the cooling channels are combined at their ends to a structure with a meander form.

7. Extrusion die according to any of claims 4 to 6, with the characteristic that the cooling channels (23-24) are applied in at least one set with two cooling blocks (16-17) which may be fastened against each other, whereby they enclose the bar shaped elements (9), whereby each of these cooling blocks (16-17) is provided with, on the one side, semicircular recesses (19-20) to enable the enclosure of the bar shaped elements 9 and on the other hand hollowings (21-22) applied transversally with respect to the recesses (19-20) and in which the cooling channels (23-24) are provided.

8. Extrusion die according to any of claims 3 to 6, with the characteristic that all cooling channels (23-24) are applied in one or more single cooling blocks whereby each cooling block has traverse bore holes, in which the bar shaped elements (9) are put.

9. Extrusion die according to any of claims 3 to 8, with the characteristic that the cooling channels (23-24) are provided with cooling fins, which are covered by means of a sheet, whereby a forced air stream is guided along the fins.

10. Extrusion die according to claim 3, with the characteristic that the cooling channels are formed by cooling fins on the cooling blocks and which are covered by means of sheets, whereby a forced air stream is guided along the fins.

11. Extrusion die according to any of claims 3 to 10, with the characteristic that the bar shaped elements (9) co-operate at one end (10) with a steady support (11), while they co-operate at their other end (12) with one of the lips (6;7) which limit the lip opening 5.

12. Extrusion die according to claim 11, with the characteristic that at least one of the lips (6;7) consists of a flexible elastic lip on which the bar shaped elements (9) with one end (12) apply a pressure, while the other ends (10) of these elements (9) push against the bolts (35), which are screwed in the steady support (11).

13. Extrusion die according to claim 11, with the characteristic that at least one of the lips (6;7) consists of a flexible elastic lip on which the bar shaped elements (9) apply a force with one end (12), while the other ends (10) are fastened at bolts (35) in the steady support (11).

14. Extrusion die according to claim 12 or 13, with the characteristic that in the die block (1) concentric recesses (37) are made around the bar shaped elements (9).

15. Extrusion die according to any of claims 3 to 14, with the characteristic that the heating elements (15) are put internally in the bar shaped elements (9).

16. Extrusion die according to claim 15, with the characteristic that the heating elements (15) consist of electric heating elements.

17. Extrusion die according to any of claims 3 to 16, with the characteristic that the control of the heating elements (15) is performed automatically by means of a measuring device which controls the local thicknesses across the complete width of the fabricated layer (4).

Revendications

1. Procédé pour le réglage de l'ouverture des lèvres d'une matrice d'extrusion pour une matière stratifiée, la matrice d'extrusion étant du type qui consiste principalement, d'une part en deux lèvres (6-7) qui réalisent l'ouverture (5) en forme de lèvre, et d'autre part en un certain nombre d'unités de commande (8) disposées sur la largeur de l'ouverture (5) en forme de lèvre, toutes étant composées d'au moins un élément (9) en forme de barre apte à se dilater sous l'action de la chaleur, respectivement à rétrécir par refroidissement, qui sont capables d'agir sur au moins une des lèvres (6-7) afin de les déplacer et de modifier l'ouverture (5) en forme de lèvre, avec cette caractéristique que le procédé de réglage consiste principalement à combiner, d'une part la commande, à l'intervention de chaque unité de commande (8), du réchauffement des éléments (9) en forme de barre en fonction des vérifications locales quant à l'épaisseur, qui sont réalisées sur la largeur de la matière stratifiée façonnée (4), et d'autre part le refroidissement commun de plusieurs unités de commande (8) en forçant un milieu de refroidissement principalement en direction transversale le long de plusieurs éléments (9) en forme de barre.

2. Procédé selon la revendication 1, avec cette caractéristique que l'on règle la température du milieu de refroidissement approvisionné.

3. Matrice d'extrusion pour l'application du procédé selon la revendication 1 ou 2, comprenant la combinaison de deux lèvres (6-7) formant une ouverture (5) en forme de lèvre le long de laquelle on peut presser la matière en continu pour obtenir une forme de couche (4); d'un certain nombre d'unités de commande (8) disposées sur la largeur de l'ouverture (5) en forme de lèvre, toutes étant composées d'au moins un élément (9) en forme de barre apte à se dilater sous l'action de la chaleur, respectivement à rétrécir par refroidissement, qui sont capables de coopérer avec au moins une des lèvres mentionnées (6-7) afin de les déplacer et d'ainsi modifier localement l'ouverture (5) en forme de lèvre; d'éléments de chauffage (15) fixés le long de chacun des éléments (9) en forme de barre et commandés par chaque unité de commande (8); et d'un moyen de refroidissement destiné à refroidir plusieurs unités de commande (8), caractérisé en ce que ledit moyen de refroidissement consiste en un ou plusieurs canaux de refroidissement (23-24) s'étendant transversalement le long des éléments (9) en forme de barre.

4. Matrice d'extrusion selon la revendication 3, avec la caractéristique que les canaux de refroidissement (23-24) sont fixés dans ou contre un ou plusieurs blocs de refroidissement (16-17) réalisés en une matière conduisant adéquatement la chaleur, qui enferment les éléments (9) en forme de barre.

5. Matrice d'extrusion selon la revendication 4, avec la caractéristique que les canaux de refroidissement (23-24) sont appliqués dans au moins un bloc de refroidissement interne et/ou au moins un bloc de refroidissement externe (16-17).

6. Matrice d'extrusion selon l'une quelconque des revendications 3 à 5, avec la caractéristique que les canaux de refroidissement sont combinés à leurs extrémités pour obtenir une structure en forme de méandres.

7. Matrice d'extrusion selon l'une quelconque des revendications 4 à 6, avec la caractéristique que les canaux de refroidissement (23-24) sont appliqués dans au moins un jeu comprenant deux blocs de refroidissement (16-17) qui peuvent être fixés l'un contre l'autre, ce qui leur permet d'enfermer les éléments (9) en forme de barre, chacun de ces blocs de refroidissement (16-17) étant muni, d'une part d'évidements semi-circulaires (19-20) pour permettre d'enfermer les éléments (9) en forme de barre, et d'autre part de creux (21-22) appliqués transversalement par rapport aux évidements (19-20) et dans lesquels on dispose les canaux de refroidissement (23-24).

8. Matrice d'extrusion selon l'une quelconque des revendications 3 à 6, avec la caractéristique que tous les canaux de refroidissement (23-24) sont appliqués dans un ou plusieurs blocs de refroidissement simples, chaque bloc de refroidissement étant muni de trous d'alésage traversants dans lesquels on place les éléments (9) en forme de barre.

9. Matrice d'extrusion selon l'une quelconque des revendications 3 à 8, avec la caractéristique que les canaux de refroidissement (23-24) sont munis d'ailettes de refroidissement qui sont recouvertes à l'aide d'une feuille, un courant d'air forcé étant guidé le long des ailettes.

10. Matrice d'extrusion selon la revendication 3, avec la caractéristique que les canaux de refroidissement sont réalisés au moyen d'ailettes de refroidissement disposées sur les blocs de refroidissement, qui sont recouvertes au moyen de feuilles, un courant d'air forcé étant guidé le long des ailettes.

11. Matrice d'extrusion selon l'une quelconque des revendications 3 à 10, avec la caractéristique que les éléments (9) en forme de barre coopèrent à une extrémité (10) avec un support fixe (11), tandis qu'ils coopèrent à leur autre extrémité (12) avec une des lèvres (6-7) qui limitent l'ouverture (5) en forme de lèvre.

12. Matrice d'extrusion selon la revendication 11, avec la caractéristique qu'au moins une des lèvres (6-7) consiste en une lèvre élastique flexible sur laquelle les éléments (9) en forme de barre exercent une pression avec une de leurs extrémités (12) tandis que les autres extrémités (10) de ces éléments (9) exercent une poussée contre les boulons (35) qui sont vissés dans le support fixe (11).

13. Matrice d'extrusion selon la revendication 11, avec la caractéristique qu'au moins une des lèvres (6-7) consiste en une lèvre élastique flexible sur laquelle les éléments (9) en forme de barre exercent une force avec une de leurs extrémités (12), tandis que les autres extrémités (10) sont fixées à des boulons (35) dans le support fixe (11).

14. Matrice d'extrusion selon la revendication 12 ou 13, avec la caractéristique qu'on réalise des évidements concentriques (37) dans le bloc de matrice (1), autour des éléments (9) en forme de barre.

15. Matrice d'extrusion selon l'une quelconque des revendications 3 à 14, avec la caractéristique que les éléments de chauffage (15) sont placés à l'intérieur des éléments (9) en forme de barre.

16. Matrice d'extrusion selon la revendication 15, avec la caractéristique que les éléments de chauffage (15) consistent en éléments de chauffage électrique.

17. Matrice d'extrusion selon l'une quelconque des revendications 3 à 16, avec la caractéristique qu'on réalise la commande des éléments de chauffage (15) de manière automatique au moyen d'un dispositif de mesure qui contrôle les épaisseurs locales sur toute la largeur de la couche fabriquée (4).

Ansprüche

1. Arbeitsweise für die Einstellung der Offnung der Lippe einer Strangpressmatrize für schichtenförmiges Material, wobei die Strangpressmatrize vom Typ ist, der hauptsächlich einerseits aus zwei Lippen (6-7) besteh,t die die Lippenöffnung (5) bilden, und andererseits aus einer Anzahl von über der Lippenöffnung (5) aufgestellten Steuereinheiten (3), alles zusanmengesetzt aus wenigsten einem stangenförmigen Element (9), das bei Erwärmung ausdehnt, beziehungsweise bei Abkühlung schwindet, geeignet um auf wenigstens eine der Lippen (6-7) einzuwirken um diese zu verstellen und die Lippenöffnung (5) zu ändern, dadurch gekennzeichnet, dass die Arbeitsweise der Regelung hauptsächlich besteht aus einer Kombination von, einerseits die Steuerung durch jede Steuereinheit (8) der Aufwärmung des stangenförmigen Elements (9) als eine Funktion der örtlichen Uberprüfungen der Stärke, die über die Breite des geformten schichtenförmigen Materials (4) ausgeführt werden, und andererseits, von der gemeinsamen Abkühlung verschiedener Steuereinheiten (8), durch Forzierung eines Kühlmittels hauptsachlich quergerichtet verschiedene stangenförmige Elementen entlang (9).

2. Arbeitsweise nach Anspruch 1, dadurch gekennzeichnet, dass die Temperatur des zugeführten Kühlmittels gesteuert wird.

3. Stranpressmatrize zur Anwendung der Arbeitsweise nach Anspruch 1 oder 2, bestehend aus der Kombination von zwei Lippen (6-1), die eine Lippenöffnung (5) bilden wo entlang das Material kontinuierlich zu einer geschichteten Form (4) gepresst werden kann, von einer Anzahl von über der Lippenöffnung (5) aufgestellten Steuereinheiten (3), alles zusammengesetzt aus wenigsten einem stangenförmigen Element (9), das bei Erwärmung ausdehnt, beziehungsweise bei Abkühlung schwindet, geeignet um mit wenigstens einer der Lippen (6-7) zusammenzuwirken um diese zu verstellen und so örtlich die Lippenöffnung (5) zu ändern, von Heizelementen (15), die jedes einzelne der stangenförmigen Elemente (9) entlang befestigt sind und von jeder der Steuereinheiten (8) gesteuert werden; und von Kühlmitteln um verschiedene Steuereinheiten (8) abzukühlen, dadurch gekenzeichnet, dass besagte Kühlmittel aus einer oder mehreren Kühlkanälen (23-24) bestehen, die sich quergericht die stangenförmigen Elemente (9) entlang ausstrecken.

4. Strangpressmatrize nach Anspruch 3, dadurch gekennzeichnet, dass die Kühlkanäle (23-24) in einem Block oder in mehreren Blöcken (16-17) oder gegen einen Block oder gegen mehrere Blöcke (16-17), aus geeignetem warmeleitendem Material hergestellt, der oder die die stangenförmigen Elemente (9) umgeben, befestigt sind.

5. Strangpressmatrize nach Anspruch 4, dadurch gekennzeichnet, dass die Kühlkanäle (23-24) in wenigstens einem inwendigen und/oder in wenigstens einem aussenliegenden Kühlblock (16-17) angebracht sind.

6. Strangpressmatrize nach Anspruch 3 bis 5, dadurch gekennzeichnet, dass die Kühlkanäle an ihren Enden zu einer meandertförmigen Struktur kombiniert sind.

7. Strangpressmatrize nach irgendwelchem der Ansprüche 4 bis 6, dadurch gekennzeichnet, dass die Kühlkanäle (23-24) in wenigstens einem Satz von zwei Kühlblöcken (16-17) angebracht sind, die gegen einander befestigt werden können, wobei sie die stangenförmigen Elemente (9) umfassen, wobei jeder einzelne dieser beiden Kühlblöcke (16-17) einerseits mit halbkreisförmigen Aussparungen versehen ist um das Umfassen der stangenförmigen Elemente (9) zu ermöglichen und andererseits mit quer zu den Aussparungen (19-20) angebrachten Aushöhlungen (21-22) und in denen die Kühlkanäle (23-24) vorgesehen sind.

8. Strangpressmatrize nach irgendwelchem der Ansprüche 3 bis 6, dadurch gekennzeichnet, dass sämtliche Kühlkanäle (23-24) in einem oder mehreren gesonderten Kühlblöcken angebracht sind, wobei jeder Block mit Querbohrungen versehen ist, in die die stangenförmigen Elemente (9) eingesteckt werden.

9. Strangpressmatrize nach irgendwelchem der Ansprüche 3 bis 8, dadurch gekennzeichnet, dass die Kühlkanäle (23-24) mit Kühlrippen versehen sind, die mit einer Platte bedeckt sind, wobei ein forzierter Luftstrom die Kühlrippen entlang geführt wird.

10. Strangpressmatrize nach Anspruch 3, dadurch gekennzeichnet, dass die Kühlkanäle von sich auf dem Kühlblock befindenden Kühlrippen gebildet werden und die mit einer Platte bedeckt sind, wobei ein forzierter Lufstrom die Kühlrippen entlang geführt wird.

11. Strangpressmatrize nach irgendwelchem der Ansprüche 3 bis 10, dadurch gekennzeichnet, dass die stangenförmigen Elemente (9) an einem Ende (10) mit einer festen Unterstützung (11) zusammenarbeiten, während sie am anderen Ende (12) mit einer der Lippen (6-7) zusammenarbeiten, wodurch die Lippenoffnung (5) beschränkt wird.

12. Strangpressmatrize nach Anspruch 11, dadurch gekennzeichnet, dass wenigstens eine der Lippen (6-7) aus einer flexibelen, elastischen Lippe besteht auf die die stangenförmigen Elemente (9) mit einem Ende (12) einen Druck ausüben, während die anderen Enden (10) dieser Elemente (9) gegen die Bolzen (35) drücken, die in die feste Unterstützung (11) geschraubt sind.

13. Strangpressmatrize nach Anspruch 11, dadurch gekennzeichnet, dass wenigstens eine der Lippen (6-7) aus einer flexibelen, elastischen Lippe besteht auf die die stangenförmigen Elemente (9) mit einem Ende (12) eine Kraft ausüben, während die anderen Enden (10) mit Bolzen (37) in der festen Unterstützung (11) befestigt sind.

14. Strangpressmatrize nach Anspruch 12 oder 13, dadurch gekennzeichnet, dass um die stangenförmigen Elemente (9) herum konzentrische Aussparungen (37) im Matrizenblock (1) angebracht sind.

15. Strangpressmatrize nach irgendwelchem der Ansprüche 3 bis 14, dadurch gekennzeichnet, dass die Heizelemente (15) inwendig in den stangenförmigen Elementen (9) angebracht worden sind.

16. Strangpressmatrize nach Anspruch 15 dadurch gekennzeichnet, dass die Heizelemente (15) aus elektrischen Heizelementen bestehen.

17. Strangpressmatrize nach irgendwelchem der Ansprüche 3 bis 16, dadurch gekennzeichnet, dass die Steuerung der Heizelemente (15) automatisch ausgeführt wird mittels einer Messvorrichtung, die die örtlichen Stärken über der Gesamtbreite der hergestellten Schicht (4) überwacht.

Drawing